Exposure biomarkers and risk from gluing and heating of polyurethane: a cross sectional study of respiratory symptoms

Objectives-To define the relation between exposure to polyurethane (PUR) gl ue, biomarkers of exposure and effect, and work related symptoms that occur at least once a week. Methods-In a cross sectional study, 152 workers and 14 clerks in a factory with exposure to sprayed and heated PUR glue containing 4,4'-diphenylmethan e (MDI) or 1,6-hexamethylene (HDI) di-isocyanate were examined with gas chr omatography-mass spectrometry (GC-MS) for metabolites of MDI in plasma (P-M DX) and urine (U-MDX), 2,4- and 2,6-toluene diisocyanate (TDI; P-TDX, U-TDX ) and HDI in plasma and urine, specific serum IgG (S-IgG-MDI, S-IgG-HDI, an d S-IgG-TDI, respectively) and IgE (S-IgE-MDI). Work related symptoms of th e eyes and airways (nose or lower airways, or both), and lung function were also evaluated. Results-P-MDX was detected in 65% of the workers, U-TDX in 47%, HDX in none . Three per cent were positive for S-IgG-MDI, 33% for S-IgG-MDI, 32% for S- IgG-TDI, and 12% for S-IgG-HDI. A few clerks had metabolites, and some had antibodies. Most metabolites and immunoglobulins were slightly correlated-f or example, P-MDX nu S-IgG-MDI: r(g)=0.21. Workers who heated glue had incr eased P-MDX (odds ratio (OR)=12 for a value above the median) and S-IgG-MDI (OR=3.7), sprayers P-2,4-TDX (OR=6.2) and F-2,6TDX (OR=16). Twenty six per cent of the workers had work related symptoms of the airways, 21% from the nose, 11% from the lower airways. Spraying of glue increased the risk of w ork related symptoms and slightly decreased lung function. U-MDX was associ ated with work related symptoms from the airways (OR=3.7) and P-2,6-TDX wit h work related symptoms from the lower airways (OR=6.6). S-IgG-MDI was rela ted to work related symptoms from the airways (OR=2.6). Conclusions There were relations between exposures to sprayed and heated PU R glue based on MDI and HDI, concentrations of metabolites of MDI and TDI i n plasma and urine, specific IgG serum antibodies against MDI, TDI, and HDI , and work related symptoms.